Table 3.

Updated Clinical Classification of Pulmonary Hypertension. Description of Groups 1-5

1 PAH

1.1 Idiopathic PAH

1.2 Heritable PAH

1.3 Drug- and toxin-induced PAH

1.4 PAH associated with:

1.4.1 Connective tissue disease

1.4.2 HIV infection

1.4.3 Portal hypertension

1.4.4 Congenital heart disease

1.4.5 Schistosomiasis

1.5 PAH long-term responders to calcium channel blockers

1.6 PAH with overt features of venous/capillaries (PVOD/PCH) involvement

1.7 Persistent PH of the newborn syndrome

2 PH caused by left heart disease

2.1 PH caused by heart failure with preserved LVEF

2.2 PH caused by heart failure with reduced LVEF

2.3 Valvular heart disease

2.4 Congenital/acquired cardiovascular conditions leading to postcapillary PH

3 PH caused by lung diseases and/or hypoxia

3.1 Obstructive lung disease

3.2 Restrictive lung disease

3.3 Other lung disease with mixed restrictive/obstructive pattern

3.4 Hypoxia without lung disease

3.5 Developmental lung disorders

4 PH caused by pulmonary artery obstructions

4.1 Chronic thromboembolic PH

4.2 Other pulmonary artery obstructions

5 PH with unclear and/or multifactorial mechanisms

5.1 Hematological disorders

5.2 Systemic and metabolic disorders

5.3 Others

5.4 Complex congenital heart disease

Reproduced with permission from Simonneau et al.⁶

LVEF = left ventricular ejection fraction; PAH = pulmonary arterial hypertension; PCH = pulmonary capillary hemangiomatosis; PVOD = pulmonary veno-occlusive disease.